CBP/p300 histone acetyl-transferase activity is important for the G1/S transition

Oncogene. 2000 May 11;19(20):2430-7. doi: 10.1038/sj.onc.1203562.


Transforming viral proteins such as E1A which force quiescent cells into S phase have two essential cellular target proteins, Rb and CBP/p300. Rb regulates the G1/S transition by controlling the transcription factor E2F. CBP/p300 is a transcriptional co-activator with intrinsic histone acetyl-transferase activity. This activity is regulated in a cell cycle dependent manner and shows a peak at the G1/S transition, suggesting a function for CBP/p300 in this crucial step of the cell cycle. Here, we have artificially modulated CBP/p300 levels in individual cells through microinjection of specific antibodies and expression vectors. We show that CBP/p300 is required for cell proliferation and has an essential function during the G1/S transition. Using the same microinjection system and GFP-reporter vectors, we demonstrate that CBP/p300 is essential for the activity of E2F, a transcription factor that controls the G1/S transition. In addition, our results suggest that CBP HAT activity is required both for the G1/S transition and for E2F activity. Thus CBP/p300 seems to be a versatile protein involved in opposing cellular processes, which raises the question of how its multiple activities are regulated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3 Cells
  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism*
  • Animals
  • COS Cells
  • Carrier Proteins*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • DNA-Binding Proteins / metabolism
  • E2F Transcription Factors
  • G1 Phase*
  • Histone Acetyltransferases
  • Mice
  • Mutagenesis
  • Protein Binding
  • Retinoblastoma-Binding Protein 1
  • S Phase*
  • Sequence Deletion
  • TATA-Box Binding Protein
  • Transcription Factor DP1
  • Transcription Factors / metabolism
  • Transcription, Genetic
  • p300-CBP Transcription Factors


  • Arid4a protein, mouse
  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • Retinoblastoma-Binding Protein 1
  • TATA-Box Binding Protein
  • Transcription Factor DP1
  • Transcription Factors
  • Acetyltransferases
  • Histone Acetyltransferases
  • p300-CBP Transcription Factors
  • p300-CBP-associated factor